Flowering time (month)
Ornamental or utility value
native wild plant
moderately dry to fresh
neutral to slightly acidic
The cornflower (Centaurea cyanus), also called cyanus, originates from the southeastern Mediterranean area. It has probably been naturalized by travellers carrying its seeds throughout Central Europe, where it has populated many grain fields ever since. This circumstance has already earned her the name cornflower in the Middle Ages. Cornflowers have become rare since more intensive fertilization of cereal fields and a high use of pesticides. They can now be found more frequently again at organically farmed field margins.
The delicate, angular stems of the annual cornflower branch loosely within a few weeks to a slender summer flower with a height between 40 and 80 centimeters.
The alternate leaves of the cornflower look different. The leaves close to the ground are usually larger than those in the upper stem area. While the lowest leaves are incised to slightly serrated, the upper ones are mostly narrow, lanceolate and with entire margins. All leaves are slightly hairy and have a fluffy feel.
The cornflower belongs to the genus Centaurea and thus to the family of composite flowers. The open round and flat inflorescence of the cornflower, botanically called the capitulum, is surrounded by a wreath of sterile tubular flowers. In nature they glow deep blue. However, there are also varieties whose tubular flowers are white, pink, carmine or deep purple in colour. As a bud, the flower is surrounded by bracts.
The achenes that are typical for the plant family develop into fruit ripeness. Each fruit has a hairy umbrella (Pappus) which spreads with the wind. The fruit is whitish to yellowish in colour and up to five millimetres long.
The cornflower thrives well in sunny places.
The summer flower loves a permeable, nutrient-poor soil.
Cornflowers can be sown directly into the bed between March and July. If you stagger the sowing dates, the flowering time will increase. The seeds should be thinly covered with soil and kept moist after distribution. Germination takes place within ten to fourteen days. In warm areas it is worth sowing cornflowers in September for early flowering next year.
Those who cut off withered flowers regularly will enjoy the uncomplicated summer flower for a long time, because it always sprouts new flowers.
The cornflower is an integral part of flower meadow and annual balcony flower mixtures and shines there together with daisies (Leucanthemum), poppy (Papaver rhoeas), mallow (Malva sylvestris), scented stoneware (Lobularia maritima) and marigold (Calendula officinalis). Fescue (Festuca) and Pearlgrass (Melica) are also beautiful companions in natural beds. The annual summer flower is often approached by bees, bumblebees and butterflies. The cornflower is well suited as a cut flower, both in fresh containers and for dry bouquets. They are also often found as a decorative addition to teas such as Lady Grey.
From the cornflower there are some beautiful sorts to buy in the specialized trade:
Blue Ball’: blue double flowers, 80 centimeters high
Blue boy’: bright blue flowers, 50-70 centimeters high
‘Rosa Ball’: filled pale pink flowers, 80 centimeters high
Black Ball’: deep purple, black flowers, 60 centimeters high
‘Red Lola’: deep pink, 80 centimeters high
‘Romantik Mix’: pink-white mixture, 80 centimeters high
The annual cornflower is propagated by sowing. After flowering – as soon as the flower heads have dried out – harvest the seeds. The small seed umbrellas are somewhat hidden inside a seed capsule, which is located under the white-furred flower capitula that has dried up. The seed umbrellas are carefully removed and stored in a paper bag in a dry place until sowing next spring.
Diseases and pests
Cornflowers retreat to overfertilized soils. They also do not tolerate permanent wetness.